JumpSystem

System Constructors

ModelingToolkit.JumpSystemType
struct JumpSystem{U<:RecursiveArrayTools.ArrayPartition} <: ModelingToolkit.AbstractSystem

A system of jump processes.

Fields

  • eqs

    The jumps of the system. Allowable types are ConstantRateJump, VariableRateJump, MassActionJump.

  • iv

    The independent variable, usually time.

  • states

    The dependent variables, representing the state of the system.

  • ps

    The parameters of the system.

  • observed

  • name

    The name of the system.

  • systems

    The internal systems.

  • defaults

    defaults: The default values to use when initial conditions and/or parameters are not supplied in ODEProblem.

  • connection_type

    type: type of the system

Example

using ModelingToolkit

@parameters β γ t
@variables S I R
rate₁   = β*S*I
affect₁ = [S ~ S - 1, I ~ I + 1]
rate₂   = γ*I
affect₂ = [I ~ I - 1, R ~ R + 1]
j₁      = ConstantRateJump(rate₁,affect₁)
j₂      = ConstantRateJump(rate₂,affect₂)
j₃      = MassActionJump(2*β+γ, [R => 1], [S => 1, R => -1])
js      = JumpSystem([j₁,j₂,j₃], t, [S,I,R], [β,γ])
source

Composition and Accessor Functions

  • get_eqs(sys) or equations(sys): The equations that define the jump system.
  • get_states(sys) or states(sys): The set of states in the jump system.
  • get_ps(sys) or parameters(sys): The parameters of the jump system.
  • independent_variable(sys): The independent variable of the jump system.

Transformations

Missing docstring.

Missing docstring for structural_simplify. Check Documenter's build log for details.

Analyses

Problem Constructors

SciMLBase.DiscreteProblemType
function DiffEqBase.DiscreteProblem(sys::JumpSystem, u0map, tspan,
                                    parammap=DiffEqBase.NullParameters; kwargs...)

Generates a blank DiscreteProblem for a pure jump JumpSystem to utilize as its prob.prob. This is used in the case where there are no ODEs and no SDEs associated with the system.

Continuing the example from the JumpSystem definition:

using DiffEqBase, DiffEqJump
u₀map = [S => 999, I => 1, R => 0]
parammap = [β => .1/1000, γ => .01]
tspan = (0.0, 250.0)
dprob = DiscreteProblem(js, u₀map, tspan, parammap)
source
DiscreteProblem(sys::DiscreteSystem, u0map::Any, tspan::Any) -> Any
DiscreteProblem(sys::DiscreteSystem, u0map::Any, tspan::Any, parammap::Any; eval_module, eval_expression, kwargs...) -> Any

Generates an DiscreteProblem from an DiscreteSystem.

source
DiffEqJump.JumpProblemType
function DiffEqBase.JumpProblem(js::JumpSystem, prob, aggregator; kwargs...)

Generates a JumpProblem from a JumpSystem.

Continuing the example from the DiscreteProblem definition:

jprob = JumpProblem(js, dprob, Direct())
sol = solve(jprob, SSAStepper())
source